Siphon Beach temporarily closed to address erosion in the bosque

The Rio Grande moved 140 feet this summer along the bosque in Corrales, bringing it within 150 feet of the levee that protects the Village of Corrales from flooding.

The Bureau of Reclamation is embarking on a project to prevent more erosion in the coming spring and protect the village’s levee, but the project will require cutting down six cottonwoods and temporarily blocking access to the popular Siphon Beach.

“I think that a lot of people don’t realize when you have a river or an arroyo, a place where water flows, it’s actually kind of a living structure. It doesn’t just stay there, unless you concrete it,” Corrales Mayor James Fahey said.

To prevent the riverbank from eroding farther west, the Bureau of Reclamation will clear vegetation. Then it will place piles of rocks that will be more than 4 feet tall, 20 feet wide at the bottom and 10 feet wide at the top. If the river’s flow leads to further erosion to the west, the rocks will fall into the river and prevent the bank from disappearing, protecting the Corrales levee.

“We’re in El Niño this year with a weather pattern. So we’re expecting a pretty good snowpack there. So, we would see more bank erosion and channel migration,” said Robert Padilla, supervisory civil hydraulic engineer with the Bureau of Reclamation.

Spring runoff typically starts in the middle of March or early April and lasts until June, Padilla said. In 2019, there was a big runoff that eroded an area downstream. But 2020, 2021 and 2022 were lighter years.

“Based on my professional judgment, there’s an even chance that the river will continue to erode to the west and it may launch the material, which would stop the erosion and migration, or there’s an even chance that it would continue to erode, but it would erode downstream, the bend would be moving downstream,” Padilla said.

Work began last week and will run through December, closing Siphon Beach and an area to the south of it along the river’s west bank. The area will reopen after the work is complete, Padilla said.

But there will be large piles of rocks along the bank south of Siphon Beach for up to two years, which will be hazardous to hike through, said Fahey, and signs will be added to discourage people from hiking among the rock piles. The rocks will remain along the bank until they fall into the river or are incorporated into a longer-term erosion project.

The Corrales Fire Department is working with Reclamation to figure out safety procedures around the rock berms, Fahey said. They’ve discussed setting aside some spots where firefighters could stage to enter the river for potential rescues, he said.

“We’re trying to figure out ways to help people avoid the area — first of all walk down there, secondly people who use rafts or innertubes or whatever, if somebody inadvertently gets down there, how do we get them out?” Fahey said. “And we’re trying to do it so that we’re protecting the people doing the saving as well as the people who need to be saved.”

Water rescuesSiphon Beach is a popular spot for launching kayaks or river rafts — a reality that created issues earlier this year when the river flow was much higher than normal. The Corrales Fire Department had to do more than 80 swift water rescues in the spring and summer.

“We’ve never had that many,” said Corrales Fire Deputy Chief Tanya Lattin, who has worked for the department since 1997.

The fire department worked with Bernalillo County and Albuquerque Fire Department, which have an air boat. The Corrales department has a boat that works well in high flows, but airboats work well in high and low flows and handle hits from tree branches better, Fahey said.

“The river was running very fast and that area eroded,” Lattin said. “We lost riverbank, which caused trees and rocks and other things to end up in the river, which caused hazards and it also pulled people into the bank by the way the river was flowing. We had people who as soon as they’d launch, they’d lose their kayaks.”

It’s hard to say if flows will be high again in the coming spring because the water level depends on rainfall and snowpack over the winter and into the spring, but the Corrales Fire Department is not leaving safety to chance. The village is purchasing an airboat for about $113,000, Lattin said.

The Bureau of Reclamation also has a long-term plan to address the erosion, which could alleviate some of the safety issues for kayakers and rafting.

The long-term project would likely start in fall of 2025. The Bureau would make a bio-engineered bank line, which would create a more gradually sloped bank. Right now, the bank in that area drops off, Padilla said.

“We’re in the middle of doing designs and planning and environmental approvals for this long-term project,” Padilla said.

It includes three bends, the Corrales bend being worked on, another bend on Sandia Pueblo and one farther down the river at river mile 199.